Process for treating ores.



W. A. TEACHER. PRooBss PoR TRBATING omas. APPLICATION FILED O0T.30,1911. RENEWED PEB. 16. 1014. 1,1 1 9,473 Patented Deo. 1,1914.

INVENTOR WTNESSES @a ride a process, which Vwill eti'eet shell with 'its lower end a short Stream o't air rei llllthllllltillD @,lflllll.,

ernten.

,Application tiled october 30, 1911, Serial No. 657.@12. Renewed February 1, 1914i.

TQ Ztl w71 om. it fm, 0 1/ Concern.

Bo it known that I, WILLIAM A. TUACHER, a, citizen of the l'nited States. residing at Lake Cityn in tht` county off Hines dale and State of Colorado.` have inventedj new and useful. lniprovenients in Processes for Treating' Dres. of Whirh the following' is; a. specification.

Myl invention relates toore-digesters, and has particular reference to the treatment ot Sultid ores; ol" gold, silver, lead. ete., with one or more acide, hut l do not liniit it to any Specific use.

it is; the object of my `ii'ivcnticun to proinixture ol Compressed air with the ore and the acid in the digester, and to @aune a. large portion ot' the acid fumes in the digrester 'to he ahsorhed, condeneotl or eouihii'iet'h and di reotly returned Ato the digesting sludge or charge in the digester, thereby Saving a. `much larger quantity of acid than is pci ble with any digester known to me.

Referring to the accompanying sheet ot'; drawing, the figure shows a central vertical section of' an oie fligester constructed in aoeorclance with the principles of my invention, some. of the parts; being Shown in eleration.

The digester comprises the shell or body l, and certain mixing apparatus; and othrr adjunctn presently to he described. 'lho shell l may ne composed of east or wrought iron or other material lined with any Suhstance with which the acids Will not chemically combine.

2 f lesigjnates u vertical nona'xorroaivo open-ended tube 'preferably composed. ol aluminum. It is :wronged centrally ol 'the lift/nee above the bottom of the shell and its upper end a short distance above the selected level, as 37 oit' the charge of ore and acid. The talig 2 may he held vertical in various Waysj the arms l suggesting one way.

5 is a valved pipe, preferably ooinpost l oi aluminum, which lentils eonipraueed air i t om4 the exterior oi' the Shell to the bottoni ol 'tolto i'v'here it; i arranged to (liz-eltern wally up "the tutte. i'u in r -\:rroaive uprfader or l'adliu over tho upper end ot the al center lino of the intuitiv "n the extension et the or anaal line of 'the tutu. il, "it un Specification et an intimato' 'apparatusA l? yoro-holder (not nhou'n),

Patent.

hatlle has; a cylindrical upper end 7 slidahle .in the sorliet or holder 8 attached to the upper end ot the shell. To tho upper end 7 ot the hallle l eonuert the lQwivel screw 9 u'hirh is threaded in the upper wall ot' the shell and is; provided with tlul actuating hand-wheel il). The lower end ol' the baille it; oonvex.

lt is the ofi-take pipe tor the acid fumes or gases, and should. in accordance with thel present prarlire. convey the fumes or rases lo a .enrichy oi ahfairption towers. in u'liieh the gaa-es are conihined with water to 'forni liquid or tree nitrie arid to he re-used in the digrutrr. de the romiverv of the acid linneo` in these towers and their return to the digitaler aro old, l have not deemed it necessary to enouniher the drawings to show the aluuirption tom-ru and other adjunctivo designates the pipe u'uiizh the arida nlay he ohaigt'ld into the di- .Co-der, 1;, lit-ing a 'valve l'or the pipe.

.l`lie oro is rharged into the Shell through the pipo 'll ox'tenilinflf through the top thereol liolou' the level olf the top ot the pipe 2, tho pipo llluingi; Supplied from an air-tiglit The pipe 14: delivers: rre helou the level oti the pipe 2 in order that the lino particles of the ore may ho wrt with the l'allinnr spray and not he rari-ital out through the otltalui pipe ll..

'l'lu lower end ol.'A the ahell tapers down uurdly no that ilu rhargje therein may flow to the ventral disvhargo opening; l5. which if; closed h uthe door or Cover lli having the lorril pivotallv commu-.ted at. one end to itl-a lower sido, 'lho lever l? in fulrrunied to the linka` t9 tout",Y one shiuvul, which are pirotally setured to a lined sul'iport. The remaining' end ot the torri' `nippori's; the rolarir screw 'lit which wol-lie in the fixed Tuut 520.

Ell is: a liaiulwlieel tor ri'ataiiug the screw. The drawing s-ihowa the discharge opening; oloeod hy the door lo. lly rotating the wu ttl in the roper direction, the outer rod ol the le rl travel upwardly and "liul mittingr tho t vpe tlirtuuih :tunnel inn ie arranged the door .lf3 and the disrharn'e opi-.ning 'lo auf :u: lo intercept the sludgy i,li jjos:ted nuiteriafl en' ping laterally und direct it di'iwnwardly in a single contracted reim; for further treatment. The funnel hy f il ti ore is fed gradually into the digesterl through the pipe 14. The. valve in the pipe 5 is opened'and a supply of compressed air passes through the pipe 5 and up the tube 2 pushing the re-acting acid and orerapidly upthe tube 2 and into contact with the convex bottom of the balile 6,- by which it is caused to spread out in a dense spray reachingthe side of the shell. Acid fumes constantly rise from the sludgy or. re-acting material in the shell and are intercepted by the said spray, whereby a large proportion ofthe acid fumes or gases are condensed, or combined with other elements to form freey acid which lfalls back to mingle with the charge in the digester and assist in the digestive process. The' operation of my digester under considerable pressure ap- .pears to be important in the working of my process, the pressure reaching Aabout 40 pounds per square inch..'depending on the rateof-feeding theore.

^ In practice the volume of the material going up the tube 2, having a diameter of one foot, 1s very large, thereby causing a violent agitation to bring all particles of orc into contact with the acid or acids of the charge and a rapid violent expansion'of the v material at the top of the tube 2. Thematerial strikes the baiile with great force causing it to be still further broken up into spray which extends entirely across the shell. The air entering through the pipe 5 leaves the shell by way of the off-take pipe 1l charged Vheaa'ily with nitric acid fumes which are recovered in a welhlknown manner in a series of absorption towers, not necessary to be described cr lillustrated.

Vhen the digestion vof the ore is nearly completed the baille 6 is raised bythe operation of the screw and the air pressure reduced in the pipe 5 by operating the valve shown therewith, or otherwise. The raising of the baille and the reducingof the air pressure preventI the formation of the spray and permit the last formed gases to rise unobstructedv and pass out the vpipe 11.

l do not limit myself to any definite proportions'of ore and acids, or to the proportlopteii of this patent maybe obtained for andere tion of the acids used. lin all casesnitric acid is used with' suld ores. @ther acids, such aysulfuric and hydrochloric acids, are used according to the nature of the ore. By my process and apparatus ll am enabled to reduce the quantity of nitric acid er charge from one-fourth to one-half of t e. amount ordinarily required, theother elements'df the charge remaining as` under the" present practice. v

v`While l do not` desire to limit myselfto the degree of pressurein thediges'terjnor to definite proportions of ingredients, 1 have found the,` following to'y be "sat'ifs'factoryf, i use about 75 pounds .of'nitric acid, corresponding to 'the reading 14,2? on lBeaums hydrometer, fer each per .centi f'sulfurin the ore; that is, if the ore shows 10% sulfur, l use about 10x75 poundsof natrc'acid. lf there are other impurities in tee-.i are beside sulfur, sulfuric acid, hydrochloric'acid, etc; Will'be used according to Well-known rules, the amounts and kinds of acid depending 'on the constitution ofthe ore.v

` lt' do not desire to be limitedto the precise details and combinationslf'shown andV descrbedas many changes maybe made with out departing from the spiiitand scope of the appended claims.`

I claim-4 1; The process of treating sulfid ores which consists 'ini causing a stream of compressed air to pass through a charge of ore `and acid in a 'closed/essel hud causing a spray of the charge to be 'snit-ad across the surface of the charge in tnpath of the acid fumes and gases rising from the charge.

2. |The process of treating sulfid ores which vconsists in mixing the ore with re acting acid in a'vessel, agitating the same vigorously during their reaction, and causing a portion of the acid .fumes to be interc epted and recovered in the vessel by a spray, the whrole being performed under a pressure greater than normal atmospheric pressure.

3. The process of treating suliid ores which consists in causing a stream of compressed air-to pass through a charge of ore and acid in a closed vessel, causing a spray of the charge to be spread across the surface ofthe charge in the path ofthe acid fumes and-gases rising from the charge, and collecting in an absorbing liquid the acid gases which pass beyond the spray.

Signed at Pittsburgh, Pa., this 27 th day of October, 1911.

VILLIAM A. TEACHER. Witnesses:

ALICE E. DUF'F, l?. N. BARBER.

:tive cents each. by addressing the Commissioner of tnatentsv Washlngtonijl. 

